1. Technical Field
The invention relates generally to a method of operating vehicle brake lights, which may include additional lights, the so-called third lights, or emergency or warning lights, and to an electronic system designed to implement this method of control, and more particularly to an improvement in light signaling to vehicles following a vehicle equipped with embodiments of the system as per embodiments of the invention through suitably intermittent, continuous, or modulated operation of brake lights.
2. Background Art
Improving the operation of brake lights is one of the most efficient means of improving road safety and reducing material losses resulting from traffic collisions. Many inventors and car manufacturers have noticed this fact and the importance of the problem and, consequently, the number of ideas and inventions in this area has increased over the last few years.
For example, U.S. Pat. No. 3,914,739B (James Daniel Caughlin; William John Ozeroff) describes a method of operating vehicle brake lights in such a way that, upon applying the brakes, the lights are turned on in an intermittent cycle, first, for example, as a series of three flashes, and then the lights stay on until the brake pedal is released. The control circuit activates a counting and pulsing unit, which generates a few pulses first and then goes into a continuous mode.
Another example is described in PCT application No. WO 00/40434A (Alhassoon, Adel, A.). It presents a system that delays the disconnection of brake lights. This system includes a timer that, after the brake pedal is depressed and released, continues to supply the voltage to brake light bulbs for some time longer. A variant of this solution, disclosed in U.S. Pat. No. 4,806,782B (Patrick J. Bernal), is a brake light control system incorporating a vehicle speed sensor. When the speed is low or continues to decrease, this system keeps supplying the voltage to the brake lights after the brake pedal is released, thus warning the trailing vehicle. At a higher vehicle speed, if there is only slight braking, the brake lights go off immediately upon release of the brake pedal.
U.S. Pat. No. 6,225,981B (Bing Kam) describes an automatic system for control of vehicle brake lights by incorporating a sensor for detecting a car approaching from behind. This system will automatically activate brake lights when the incoming vehicle approaches to a dangerously close distance. If the distance between the vehicles increases sufficiently, the lights will go off automatically unless the brake pedal is depressed at the same time.
PCT application No. WO 01/00444A (Ortiz Aldama, Juan Manuel; et al.) describes another system that controls brake light operation in the case of hard braking or a head-on collision. The system incorporates a negative acceleration (deceleration) sensor, which, upon detecting hard braking, automatically activates pulsating brake lights. The system features a back-up power supply that allows further generation of warning pulses when the electric supply system of the vehicle becomes damaged as a result of head-on collision. A variant of this solution, disclosed in patent application PL 293111A (Kokosza Jan Mieczyslaw; Wenta Marek), is a system equipped with a multi-threshold mercury sensor that increases the intensity of warning as the braking force becomes greater.
Finally, GB 2269493A (Peter William Neale) describes another brake light control system fitted with a sensor detecting both the pressure exerted onto the pedal and the time interval during which this pressure is applied. When preset values of these parameters are exceeded, the system automatically activates emergency lights and warns the driver of a trailing vehicle that a reduction of speed is urgently needed. After the brake pedal is released, the system returns to a normal state of activating the brake lights only due to the brake pedal movement.
The above inventions generally require the application of special sensors and circuits in various positions on the vehicle. This requirement can be quite expensive. Further, mounting these sensors can be difficult, especially when this is not done during vehicle manufacture. Additionally, some of the above inventions create lights where the flashing is too frequent, for example in downtown driving or on congested roads. This may result in excessive eyestrain and impaired perception of the trailing drivers. This adverse effect is a disadvantage of the previously mentioned inventions.
There is thus a need for an improved brake warning system.